<!DOCTYPE html>
<html>

	<head>
		<meta charset="utf-8">
		<title></title>
	</head>

	<body>
		<a href="1_1.html">水平堆叠</a>
		<br />
		<a href="1_2.html">中型和大型设备</a>
		<br />
		<a href="1_3.html">手机、平板电脑、台式电脑</a>
		<br />
	</body>

</html>